The main reason given for imposing wind turbines upon us is that they displace fossil fuel carbon dioxide (CO2) emission. The BWEA claims that wind generation displaces 0.86 tonne CO2 per megawatt-hour (MWh) of coal-fired CO2 emission. This is deliberately misleading. The true figure is the displacement of emission from the average of "coal-fired + gas-fired" generation. It is 0.58 t CO2 per MWh.* These two figures are absolute maxima as they are not corrected for the emission of CO2 by the reserve generation necessary to back up intermittence of wind. This is now accepted as at least 0.3 to 0.5 times the installed wind generating capacity.

Web link: http://www.aweo.org/windEtherington.html